1. Field of the Invention
The present invention relates to a multi-directional input unit, and more particularly, to a multi-directional input unit which accepts inputs in a plurality of directions by pressing down various positions of the keytop.
2. Description of the Related Art
A known multi-directional input unit 100 show in FIG. 10 includes a circular keytop 170 fitted in a push slide 150 and disposed in an outer chassis 180, a rotary plate 132 and chassis portion 121 mounted in the push slide 150, a first switch portion 110f in a center portion and a second switch portions 110b, 110d in an outer peripheral portion formed in a dome shape and mounted on a switch substrate 110.
In an initial state of a horizontal operating surface 170a of the keytop 170, when an outer peripheral portion of the operating surface 170a is pressed in a direction indicated by an arrow A, as a first operation, the keytop 170 is inclined in the direction indicated by arrow A.
The push slide 150, the rotary plate 132, and the chassis portion 121 are inclined along with the inclination operation of the keytop 170, and a convex portion 121h in the outer peripheral portion of the chassis portion 121 presses down the dome-shaped second switch portion 110b with a predetermined operating force. Accordingly, the second switch portion 110b is activated by the pressing operation.
When the pressing force in the direction indicated be arrow A is released, the push slide 150, the rotary plate 132, the chassis portion 121, and the keytop are restored to the initial state by an elastic bias of the dome-shaped second switch portion 110b. 
Accordingly, the second switch portion 11b is deactivated. When the outer peripheral portions of the operating surface 170a are pressed down, the keytop 170 is inclined in a respective direction, whereby a projection portion 121h of the chassis 121 allows the second switch portions 110b, 110d to be on.
According to the known input unit 100 shown in FIG. 11, in an initial state of the horizontal operating portion 170a, the center portion of the keytop 170 is pressed in a direction indicated by an arrow B. Then, the push slide 150 resists an elastic force of a slide restoring spring 140 and moves downwardly, whereby a convex portion 150d of the push slide 150 presses down the first switch portion 110f of the switch substrate 110. Accordingly, the dome-shaped the first switch portion 110f is inverted and toggled.
An operator feels a click accompanying the inversion of the first switch portion 110f, whereby the operator can realize that the first switch portion 110f is toggled.
When the pressure in the direction of arrow A of the keytop 170 is released, the keytop 170 is automatically restored in the original initial state by an elastic force of the first switch portion 110f and an elastic force of the slide restoring spring 140.
Accordingly, the first switch portion 110f is deactivated.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2001-345031
However, according to the above-mentioned known input unit 100, since the first switch is inverted and toggled by pressing down the keytop 170 against the elastic force of the slide restoring spring 140, the click felt by the user when the first switch portion 110f is inverted is absorbed by the slide restoring spring 140, causing the generated click to be weakened. Accordingly, it is difficult to realize whether the first switch is toggled.
In addition, in case of an input of the first switch portion 110f or the second switch portion 110b, when the pressed position on the operating surface 170a of the keytop 170 is not uniform and when the first switch portion 110f and the second switch portions 110b, 110d are operated at the same time, error inputs may occur.